Aerostat



oct. 14, 1930, H SCOTT ET AL 1,778,692

AEROSTAT Filed Dec. 15, 1927 2 sheets-sheet; 1-

WW/Mw Oct. 14, 1.930. G. H. SCOTT ET AL 1,778,592

AEROSTAT Filed Dec. l5, 1927 2 Sheets-Sheet 2 d /fw `or the like.

Patented Oct. 14, 1930 rrr Lorsica y,

GEORGE HERBERT SCOTT AND FREDERICK MICHAEL ROPE, OF CARDINGTON,^`EN GLAN D AEROSTAT Applicatipn med' December 15, 1927, serial No. 240,32o,'and in Great Britainrebraryie, i927.V

rlhis inventionv relates to aerostats and more particularly to automatic valves or valve systems for releasing gas when the pressure of gas in the gas bags has reached aV predetermined limit, or when they are full and at a slight superpressure Hitherto, it has been the usual practice to lit gas valves at or near the bottom of the gas bags, the valves being maintained in a closed position by means 'of lightv springs The chiefobjections to the known arrangement are (l) The valve floats up with the bottom of the gas bag when the bag is only partiallyfull of gas.

(2) Owing to the small super-pressure at the bottom of the bag at which thev valve has to operate, there is a diiculty in designing a valve to give a reasonable lift as compared 1 with the diameter of the valve, so that in large gas bags valves of a very large diameter, or alternatively a large number of valvesfmust be fitted, and chattering of the valve on its seating is liable vto occur.

(3) A large area.` of opening 1s necessary to the small super-pressure at the' bottom of the bag available ordriving the gasthrough the valve. r

(4) It is difficult Vto `adjustthe 'light valve-closing springto operate at the correct pressure under all conditionsi..

The present invention hasfor its( object to overcome the above mentioned objections and to obtain. other advantages.'

According to one feature y'of theinven-Y tion, an automatic gas valve for an-*aerostat gas bag is constructed and arranged so as to be approximately balancedfasregards jdirectly transmitted Vgas pressure from the gas bag, but so as to have a small resultant positive tendency to close. With this arrangement the pressure betweenthe Vvalve and its seating is proportionall to the presf sure in the gas bag vforanypressurein vthe gas bag lower than that at which the valve is designed to open. To the'closing force duetoa-the gas pressure an additional'lforce independent of gas pressurelmay "be`provided, if desired, by aspring orother means.

According toranother feature 'of the invention, ay collapsibleand expansible control chamberV is provided for opening a-gas valve for an aerostat gas bag ina`V decisive manner and to`-l theull extent underpredetermined conditions of pressure `in the gas bag. The control lchamber may vbe combined with the 1valve so Yas tofminimize-the number of moving parts.

rAccording to another featurefothe invention, the valve is arranged above the bottom of the gas bagand'an operating pipe` is provided ki'or bringing about pressure'in the control chamber, the pipeservingfto comes charged with gas for opening'the valve at a predeterminedr'gas' leveli or *gas pressure in the Vgas bag. to `discharge any givenvolume of gas owing According to another v'feature of the` invention, one or more leaks are'provid'ed in in association 'with the'op'erating' pipe for opening the valve at--apredetermined lp'res- Sure.

v'ilccording tofvanother `feature of the invention, an auxiliary hand-operated valve is associated' withl the .operating pipe, or with the-.control chamber and the VVgasbag' for operating the" `au'foniatic valve iiormanuvring' or other purposes.A i

ful

(ht aangaat oi nubilato git* uit or gas valve system according to the present invention is shown diagrammat-ieally and by way of example in the accompanying drawings, in which Fig. l is an elevation showing the valve or valve system in situ on a gas bag, Fig. 2 is an enlarged view ot the valve and its connections; and Fig. 3 is a detail sectional view ot the lower portion ot' the valve showing the same in open position.

As shown, a gas bag A is titted with a valve B in a position approximately at the horizontal diameter or the gas bag. lt should be understood, however, that the valve position can be at the top or at any distance below the top oli the gas bag, but is preterably above the highest level to which the bottom ot the gas bag can rise during flight et the aerostat. rl`he higher the valve position, the greater is the` rate of discharge ot' the gas from the gas bag Yfor any given size et valve. The valve is preferably placed so as to be readily accessible during flight.

A U-shaped operating or control pipe C communicates at one end with the gas bag at point near the valve position, and at the other end with a control chamber J associated with the valve B. The looped part ol the operating pipe is carried to a point at or near the bottom ot the gas bag when full, or when full and at a slight super-pressure.

t'this point is level with the bottom ot' the gas bag, the valve will operate as soon as the gas bag is full et It on the other hand, as shown, the point, namely D, is situated at a vertical distance 00 below the bottom ot the gas bag, the valve will operate when the super-pressure at the bottom of the gas bag is determined by the value or' the distance au. By these means it is possible to regulate the super-pressure at which the valve will operate by altering the level of the point D.

A leal; or vent indicated by the dotted lines at D is provided at D, so that as soon as the super-pressure decreases below that due to the distance a3 of the point D below the bottom ot the gas bag, air is permitted to enter the operating pipe and prevents siphonic action. Alternatively, the operating pipe C may be ot such strength laterally as to collapse as soon as the supe 1-pressure decreases below that due to the distance of the point D below the bottom et the gas bag, thereby preventing siphonic action.

The automatic valve proper preferably consists of an outer stit'f diaphragm B having` a conical or conoidal central portion and cylindrical peripheral portion which carries a valve tace F constructed in the form of an annular plate. The valve B, torming a part ot the diaphragm B, is mounted its centre on a tubular axial guide M which is supported at the centre or hub M2 of a spider M fixed in the aperture in the wall of l l l l 'Il l l l v i i l l lh ai lag. lh@ uit: tu l, wat lN 1. attached to the outer diaphragm B and moves with the valve, sits upon a seating E constructed in the term et a cylinder and liXed in the gas bag aperture at X in any convenient gas-tight man cr. A stili' diaphragm G ot conical or conoidal form is lixed to the hub or the spider and is connected with the movable valve tace F by means of a collapsible bellows l-l or equivalent means attached Vto said valve tace. Normally, the movable valve cone nests near to the lixed diaphragm cone as shown. chamber l3 is formed, bounded by the valve tace l", the bellows lll and the diaphragm G, and this chamber is open at "il to the pressure from the gas bag fr, and a chamber J is formed, bounded by the diaphragm B, the bellows H and the diaphragm G, and this chamber is open at Z, Z', through the tubular guide M to the operating pipe C at the point L.

yl`he movable valve face F is pressed upon the liXed valve seating E by the pressure treni the gas bag in the chamber P, owing to tneir being superimposed on the valve tace E (in addition to the balanced direct pressures trom the gas bag acting on opposite sides ot the valve tace) the indirect pressure from the gas bag acting on the bellows andtending to expand them in the axial direction to close the valve. las shown, the einer diameter Z ot the bellows is greater than the diameter cl2 of the valve seating, which is equal to the diameter ot the connection between the bellows and the valve. The pressure ot the movable valve face on the lined seating is thus proportional to the pressure in the gas bag.

-When pressure trom the gas bag passes through the operating pipe C into the chamber J, owing to the bottom of the bag descending to the point D, the pressure op erating on the central portion ot the movable outer diaphragm B rapidly lifts the valve face F from the seating E to the full extent of the outward motion ot the valve B along the tubular guide M.

A small leal; to the outer air may be provided at the highest pointI of the operating pipe, at L from the inside ot the tubular guide M, or from the control chamber', so that when the operating pipe C ceases to supply gas to the chamber J owing to the bottom ot the gas bag rising above the point D, the gas leaks away to the atmosphere, bringing the pr sure in the chamber J back to atmospheric pressure.

Y A spring K, interposed between an abutment on the outer end of the tubular guide lvl and abutting the outer tace of' the valve B', then returns the valve face F on to the seating E, and as soon as contact takes place the closing pressure,` due to the diameter fl beir j greater than the diameter Z2 as above mi., tioned, once more comes into action. Even that on the inner side, due to the action of the jet of gas issuing from the gas bag -v through the opening Y.

fitted on the inner end of the cylindrical seating, to increase the coefficient of discharge of the valve. The funnel-shaped entrance has the effect of virtually increasing the diameter (Z2 of the valve seating.

To facilitate the movement of the valve B along the guide M, an axial ball cage S or a system of rollers is tted between the guide and a tubular boss T at the centre of the valve.

The operation is as follows Supposing the gas bag A to be half full of gas which is lighter than air, such gas will occupy the upper` half of the bag and will have an approximately horizontal lower surface. If now the bag be progressively filled, the gas will enter the inner liinb of the pipe C and will Ydescend in this pipe as far as the level of the gas in the gas bag. As the filling of the bag with light gas proceeds, gas will eventually reach the point D of the pipe C. This will occur before thebag is full if the point D be place-d above the level of the bottoni of the bag. lf, on the other hand, the point D be placed below the bottom of the bag, gas will reach the point D in the pipe C when the pressure at the bottom of the bag is equal to the difference of densities of air and gas multi' plied by the vertical distance between the point D and the bottom of the bag, as indicated by 00. V point D, it will at once pass up the outer limb of the pipe C into the chamber J of the valve. ln this chamber, the gas develops a pressure above the surrounding air which is rather less than the pressure of the gas at the same level in the bag, owing tothe leak L, but is sufficient to open the valve by acting on the central portion of the movable outer diaphragm B in the manner hereinbefore described. If now the pressure at the bottom of the-gas bag is reduced or the lower surface of the gas in the bag commences to rise, or both of these changes occur, the pressure of the gas at the point D in the pipe C will fall below that of the surrounding air. If the pipe C were rigid, gas would continue to flow through such pioe, maintaining a flow through the leak L and a pressurein the chamber J, but owing to the fact that the pipe C is either collapsible or is provided with the vent D at D, as hereinbefore described, it will either collapse and thus prevent further flow of the gas or air will enter through the vent D and thereby destroy siphonic action of the gas through the legs of the U-shaped pipe C into the chamber J of the valve, and

i the leaking oif of the gas from the chamber Then the gas does reach theV Jthrough the'vent L will cause the pressure in saidchamber to drop to atmospheric and allow the valve toclose in the manner hereA inbefore described.

g In another modification, the valve maybe made to be operatedbyhand, whateverV the .degree of fullness ofthe gas bag, by fitting A flared or funnel-shaped entrance N is` a smallhand-operatedcross connection valve O between the two legs of the operation pipe,

orby-equivalent meansffor obviating the necessity of fitting separate manoeuvring valves in an airship.

Having thus described the nature of the said invention and the best means we know of carrying the saine into lpractical effect, we claim l. An automatic gas valve for an aerostat gas bag, comprising a valve face plate subject to the direct pressure of the gas bag on both faces, a seat for said face plate, and means actuated by the pressure of the gas bag operating to close the valve face plate.

2. An automatic gas valve for an aerostat gas bag comprising a valve face plate subject to the direct pressure of the gas bag on both faces, and a collapsible and expansible chamber communicating with the interior of the gas bag and attached at its free end to the valve face plate.

43. An automatic gas valve for an aerostat gas bag according to claim l, having associated with it a collapsible and expansible control chamber, and a conduit capable of venting to the atmosphere and connecting said chamber with the interior of the gas bag.

4. An automatic gas valve for an aerostat gas bag according to claim l, arranged above the bottom of the gas bag and having associated with it a collapsible and expansible control chamber, and a pipe serving to connect the control chamber with the gas bag and acting as an operating or siphon means, said pipe being provided with means to enable the pressure in the control chamber to fall and allow the valve face plate to close when the` conditions causing it to open cease to exist.

5. An automatic gas valve for an aerostat Y gas bag according to claim 1 arranged above the bottom of the gas bag and associated with a collapsible and eXpansible control chamber, and a pipe` serving to connect the control chamber with the gas bag and acting as an operating or siphon means, and an auX- iliary hand-operated valve associated with said pipe. v

6. An automatic gas valve for an aerostat gas bag according to claim 1, comprising a valve face plate in the form of an annular plate, a stationary stiff` diaphragm, and a collapsible bellows connecting the said stationary diaphragm with the annular plate and thereby forming a chamber communi-V valve face plate in the form of an annulai` plate, a stationary stili diaphragm andra collapsible bellows connecting the said stationary diaphragm with the annular plate, an outer stili and movable diaphragm also connected with the annular plate, said outer diaphragm enclosing said collapsible bellows, and a pipe connecting the interior of the gas bag with the chamber enclosed between the said outer diaphragm and the said bellows.

In testimony whereof We have signed our names to this specification.

GEORGE HERBERT SCOTT.

FREDERICK MICHAEL ROPE 

